1. Technical Field
The present disclosure relates to airplane ground deicing installation systems and methods and, more particularly, to deicing installation systems and methods that advantageously minimize the impact of an airplane's deicing treatment on the operation of an airport, e.g., during icing and/or snow conditions.
2. Background Art
Deicing of airplanes is a major contributor to winter-related air traffic delays. The ripple effect extends far beyond the weather-affected area, such that the costs to the airlines are in the order of billions of dollars each season, while the effect on the economy is much higher.
Currently available deicing technologies have been unable to eliminate the delays and associated issues related to airplane deicing operations. The overwhelming majority of the deicing operations are performed nowadays by deicing trucks that spray the airplanes' contaminated surfaces with deicing and anti-sticking fluids. The use of deicing trucks may derive from historical use of fire-fighting trucks to dispense glycol on glycol-cooled engines. Regardless of the genesis of deicing truck-based operations, the efficiency and efficacy of such operations are limited and in need of significant improvement.
According to conventional deicing operations, deicing fluids are heated and their concentration is controlled as a function of the type of frozen contamination and of the atmospheric conditions at the time of deicing. Sometimes air jets or heat radiators are also used to save deicing fluids that are not only expensive, but they have adverse environmental effects too.
Anti-sticking fluids are typically applied in a limited period of time after deicing, to prevent further precipitation to accumulate on the surfaces of deiced airplanes that cannot take off immediately after being deiced. The anti-sticking treatment is generally effective for a pre-determined period of time and, if that hold over time is exceeded, deicing must be repeated.
Delays are inherent in the use of deicing trucks simply because there is a limit on how many trucks can simultaneously work safely around an airplane. Deicing trucks also have an efficiency limitation as they apply the deicing fluids from a relatively large distance from the surface to be deiced.
There are at least three factors that can contribute to a deicing operation: a chemical factor, a thermal factor, and a mechanical factor. The efficiency of the last two effects diminishes rapidly as the distance from the dispenser to the surface to be deiced increases. Wind, a frequent factor on open spaces such as airport runways, is an aggravating factor that affects all aspects of truck-based deicing operations.
Applying fluids from shorter distance is not necessarily a solution for the deicing trucks since deicing will take even longer due to the need to traverse the perimeter of the airplane with the deicing truck(s) to apply deicing solution to all necessary surfaces.
Deicing time longer than the separation time in between take-offs requires that several airplanes are simultaneously deiced on several designated spots, off the taxiway, and this operational requirement entails longer taxi routes that translate into inconvenience, cost and even longer delays.
At major airports, numerous deicing trucks are needed in order to sustain the air traffic. The numerous deicing trucks around airplanes represent an additional hazard due to the potential for mishap, and their presence on the tarmac further increases the load/responsibility of ground traffic control personnel.
Numerous attempts have been made to improve airplane ground deicing operations. Prior attempts have been unsuccessful, however, as demonstrated by the fact that deicing truck-based operations are still the overwhelmingly-used airplane deicing technology.
The patent literature reveals additional efforts to improve the design and operation of airplane deicing operations. For example, the following patents/patent publications provide background teachings relative to the systems and methods of the present disclosure:                U.S. Pat. No. 3,533,395 to Yaste        U.S. Pat. No. 3,460,177 to Rhinehart et al.        U.S. Pat. No. 3,612,075 to Cook        U.S. Pat. No. 4,378,755 to Magnusson        U.S. Pat. No. 4,634,084 to Magnuson        U.S. Pat. No. 5,060,887 to Kean        U.S. Pat. No. 5,104,068 to Krilla et al.        U.S. Pat. No. 5,161,753 to Vice et al.        U.S. Pat. No. 5,354,014 to Anderson        U.S. Pat. No. 5,458,299 to Collins et al.        U.S. Pat. No. 6,038,781 to McElroy et al.        U.S. Pat. No. 6,092,765 to White        U.S. Pat. No. 6,820,841 to Mittereder et al.        WO 2001/092106 to Foster et al.        
A summary of the difficulties and a general description of the most common pitfalls of the previous designs is provided herein. The noted pitfalls help to explain why none of the previous deicing installation designs aiming for high speed deicing have achieved general acceptance from the airlines and/or airports.
Airplane deicing is a complex process itself as the nature of the ice/snow contamination could widely vary subject to many weather-related factors, including precipitation type and quantity, temperature, relative humidity, wind direction and intensity. Operational factors also have a substantial impact on deicing operations, such as full or partially full tanks, after landing cold fuel, or “warm” after fueling up, parked position in respect to wind and the like.
However, it is not the complexity of the deicing process that is the main contributor to the failure of the previous attempts to build airplane ground deicing installations capable of deicing speeds such that to minimize the impact on airport operations during winter weather. The passenger airplanes operating from major airports are of large variety in size and shape, winglets representing a special challenge, and no prior attempt has succeeded in accommodating such a wide variety of airplane shapes/sizes/configuration while meeting all airports' and airlines' deicing requirements.
The majority of the installations intended to achieve high deicing speed and accommodate the largest airplanes have been fixed type installations entailing modified taxi patterns which entails delays and fuel burned to navigate to and from the installation.
Besides the inherent disadvantages resulting from a fixed type design, most designs for large installations require a precise, time consuming, positioning of the deiced aircraft relative to the source of deicing fluid, and have a low deicing fluid usage efficiency as a result of designs with substantial limitations to adapt to the different sizes, shapes, configurations and types of aircraft.
Some of the fixed installations have been hangar-type designs that improve the deicing speed and, up to a point, the deicing efficiency for larger airplanes. One particular hangar-type installation used heat radiation for deicing, eliminating the use of deicing fluids, but the deicing time was longer than the separation time between take-offs and therefore, several such installations would be needed to serve a busy airport where available terrain is an issue. Taxi pattern would also needed to be altered to accommodate such operations and airplanes deiced by this installation still required anti-sticking fluids.
Despite efforts to date, a need remains for high efficiency and high speed airplane deicing systems and methods that accommodate airplanes of different size, shape and configuration. Moreover, a need remains for deicing systems and methods that efficiently utilize deicing fluids despite environmental conditions, e.g., variable wind conditions, and that do not negatively impact other airport operations, e.g., timing between flight departures. Still further, a need remains for deicing systems and methods that demonstrate attention to the environment, most precisely to the recovery of deicing fluids. These and other objects are satisfied by the advantageous deicing systems and methods of the present disclosure.